#include <iostream>
#include <stdlib.h>
#include <string.h>
using namespace std;
int main(int argc, char*argv[])
{
  if(argc != 2)
  {
    cout<<"can not execut"<<endl;
  }
  cout<<"获取的环境变量是："<<getenv("MY_VAL") << endl;
  if(strcmp(argv[1], "-a") == 0)
  {
    cout<<"function a" << endl;
  }
  else if(strcmp(argv[1], "-b") == 0)
  {
    cout<<"function b" << endl;
  }
  else 
  {
    cout<<"default!"<<endl;
  }
  return 0;
}
